The present invention relates to a novel tumor-associated antigen that is a cell-surface glycoprotein having a molecular weight in the range of 110,000-140,000 daltons and that is present in a variety of carcinomas, including squamous cell carcinomas and adenocarcinomas. The invention also comprises antibodies reactive with the antigen, hybridoma cell lines that produce the antibodies of the invention, and methods for using the antibodies in the diagnosis and treatment of cancer.
The lymphocyte hybridoma technique described by Kohler and Milstein (Nature 256:495-497, 1975) has enabled the isolation of monoclonal antibodies directed against a vast array of antigenic targets. Many laboratories have taken advantage of hybridoma technology to produce monoclonal antibodies which bind to tumor-associated antigens from a large number of tumor types, including tumors derived from lung, liver, colon, breast, kidney, bladder, skin, brain, prostate, and lymphocytes (reviewed by Sulfitzeanyu, 1985, Advances in Cancer Research 44:1).
Monoclonal antibodies reactive with tumor antigens have been used for a variety of diagnostic and therapeutic purposes. Monoclonal antibodies labeled in a variety of ways serve as useful reagents in the detection, diagnosis, and treatment of carcinomas. The particular labeling technique used to conjugate the antibody to the label depends on the purpose for which the conjugate was made. Fluorescent, radioactive, and enzymatic labels are commonly used to detect and diagnose disease states, while monoclonal antibodies designed for therapeutic purposes are often labeled with radioisotopes or chemical and biological agents. In all cases, the binding of a labeled monoclonal antibody to the appropriate antigen will signal detection of the cellular target or delivery of the conjugate to the cellular target.
Early diagnosis of malignancies and the identification of tumor-type is critical to the clinical management of carcinoma. The present invention comprises monoclonal antibodies reactive with an antigen expressed on human carcinoma cells. Although production of monoclonal antibodies reactive with carcinomas is described in U.S. Pat. No. 4,708,930; European Patent Publication 157,613; Mazauric et al., 1982, Cancer Research, 42:150; Brenner et al., 1982, Cancer Research, 42:3187; Mulshine et al., 1983, The Journal of Immunology, 13161:497; and Masuko et al., 1985, Japanese Journal for Cancer Research 76(5):386, no monoclonal antibodies reactive with the antigen of the present invention have been described. All squamous carcinomas of the lung, head, and neck, and adenocarcinomas of the colon and lung, express the antigen and therefore react with the antibodies of the invention. The broad distribution of the L/1C2 antigen on human carcinomas demonstrates the significant diagnostic and therapeutic applications of this invention.